In April 2019, the Company entered into a Research Collaboration and License Agreement (the Lilly Agreement) with Eli Lilly and Company (Lilly) for the discovery, development and commercialization of AOC products directed against certain targets in immunology and other select indications on a worldwide basis. Under the Lilly Agreement, the Company granted Lilly an exclusive, worldwide, royalty-bearing license, with the right to sublicense (subject to certain conditions), under the Company’s technology to research, develop, manufacture and sell products containing AOCs that are directed to up to six mRNA targets. The Company retains the right to use its technology to perform its obligations under the Lilly Agreement and for all purposes not granted to Lilly. The Company agreed that it will not, itself or with a third party, research, develop, manufacture or commercialize or otherwise exploit any compound or product directed against targets subject to the Lilly Agreement.

In consideration of the rights granted to Lilly under the Lilly Agreement, the Company received a one-time upfront fee of $20.0 million and is eligible to receive up to $60.0 million in development milestone payments, up to $140.0 million in regulatory milestone payments and up to $205.0 million in commercialization milestone payments per target. In addition, Lilly is obligated to reimburse the Company for research expenses, as defined in and incurred under the Lilly Agreement. Lilly is obligated to pay the Company a tiered royalty ranging from the mid-single to low-double digits on worldwide annual net sales of licensed products, subject to specified and capped reductions for the market entry of biosimilar products, loss of patent coverage of licensed products and for payments owed to third parties for additional rights necessary to commercialize licensed products in the territory. Lilly’s royalty obligations and the Lilly Agreement will expire on a licensed product-by-licensed product and country-by-country basis on the later of ten years from the date of the first commercial sale or when there is no longer a valid patent claim covering such licensed product in such country.

The Company has identified multiple promises to deliver goods and services, which include at inception of the agreement: (i) a license to technology and patents, information and know-how; and (ii) collaboration, including research services, technical and regulatory support provided by the Company. At inception and through December 31, 2020, the Company has identified one performance obligation for all the deliverables under the Lilly Agreement since the delivered elements are either not capable of being distinct or are not distinct within the context of the contract. Accordingly, the Company will recognize revenue for the fixed or determinable collaboration in an amount proportional to the collaboration expenses incurred and the total estimated collaboration expenses over the five-year period over which it expects to deliver its performance obligations. The Company periodically reviews and updates the estimated collaboration expenses, when appropriate, which adjusts the percentage of revenue that is recognized for the period. In connection with the Lilly Agreement, the Company recognized revenue of $6.8 million, $2.3 million and $0 for the years ended December 31, 2020, 2019 and 2018, respectively, and had deferred revenue of $15.8 million and $18.9 million as of December 31, 2020 and 2019, respectively. Collaboration receivables related to the Lilly Agreement were $1.2 million and $0.8 million as of December 31, 2020 and 2019, respectively, which are included in prepaid and other assets on the balance sheets.

A reconciliation of the closing balance of deferred revenue related to the Lilly Agreement is as follows (in thousands):

Balance at December 31, 2018	$	—
Upfront payment		20,000
Revenue recognized		(1,060	)
Balance at December 31, 2019		18,940
Revenue recognized		(3,100	)
Balance at December 31, 2020	$	15,840

Concurrently with the execution of the Lilly Agreement, the Company issued a convertible promissory note to Lilly (the Lilly Note). In connection with the Series C financing in November 2019, all outstanding principal and interest accrued under the Lilly Note converted into 4,576,342 shares of Series C convertible preferred stock. See Note 8 (Convertible Notes) for further discussion.

In December 2020, the Company entered into a research collaboration (the MyoKardia Agreement) with MyoKardia, Inc. (MyoKardia), a wholly-owned subsidiary of Bristol Myers Squibb, to demonstrate the potential utility of AOCs in cardiac tissue by leveraging MyoKardia’s genetic cardiomyopathy platform including, among other aspects, its novel target discovery engine and proprietary cardiac disease models. As of December 31, 2020, the Company has not received any payments or recognized any revenue under the MyoKardia Agreement.

In 2016 and 2017, the Company entered into agreements with pharmaceutical companies under which the Company was contracted to perform certain research and development activities, as defined in work plans. All work under the agreements was completed in early 2018 with the Company recognizing revenue totaling $0.4 million for the year ended December 31, 2018.